State radio announced that he had attended the completion ceremony of an amusement park with his wife, Comrade Ri Sol-ju, according to Voice of America. It is not clear when the pair married.

Kim became leader following the death of his father Kim Jong-il late last December and took the top military rank of marshal this month – days after the sudden departure of army chief Ri Yong-ho – in a symbolic cementing of his status.

Professor Hazel Smith, an expert on North Korea at Cranfield University, said: “It looks as if they have been following a very systematic sequence of events.” Kim is thought to be 27 or 28 and his wife also appears to be in her twenties or early thirties.

Earlier, the South Korea’s unification minister, Yu Woo-ik, had said that the woman repeatedly shown with him “appears to be his wife”, AFP reported, although he did not indicate why he thought so.